I have been trying out various low clearance avoidance tools after witnessing a horrible accident and having a close call myself. Obviously I look out for the signs ahead, but not all bridges are posted and it's no good for planning a route anyway.

So what are the options?

Rand McNally Motor Carrier Road Atlas

Pros - Much more than a low clearance list, with an abundance of useful information.

Cons - Limited to just over 1000 low clearances. Can't use while driving. Costs around $50.

Nice work! If only there was a way to merge the free databases and weed out the duplicates... sounds like a project that we could all benefit from. Is there a way to divvy this up among interested members?